System.Xml.Serialization.XmlIgnoreAttribute Class

Summary

Instructs the XmlSerializer.Serialize method of the XmlSerializer not to serialize the public field or public read/write property value.

C# Syntax:

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter | AttributeTargets.ReturnValue)] public class XmlIgnoreAttribute : Attribute

The XmlIgnoreAttribute belongs to a family of attributes that controls how the XmlSerializer. serializes, or deserializes, an object. If you apply the XmlIgnoreAttribute to any member of a class, the XmlSerializer ignores the member when serializing or deserializing an instance of the class. For a complete list of similar attributes, see the conceptual topic at MSDN: attributesthatcontrolserialization.

You can override the behavior caused by the XmlIgnoreAttribute by creating an XmlAttributes object, and setting its XmlAttributes.XmlIgnore property to false. You must XmlAttributeOverrides.Add the XmlAttributes object to an instance of the XmlAttributeOverrides class. Lastly, you must use the XmlAttributeOverrides object to construct an instance of the XmlSerializer class before you call the XmlSerializer.Serialize or XmlSerializer.Deserialize methods.

The the conceptual topic at MSDN: xmlschemadefinitiontoolxsdexe occasionally generates the XmlIgnoreAttribute when creating classes from a schema file (.xsd). This behavior occurs because value types cannot be set to null, but all XML data types can be. Therefore, the tool creates two fields when it encounters an XML type that maps to a value type: one to hold the value, and another, special field that takes the form of fieldnameSpecified, where the fieldname is replaced by the name of the field or property. Notice, however, that this special field is generated only when the schema specifies that the element need not occur (minOccurs = "0") and that the element has no default value. The XmlSerializer sets and checks this special field to determine whether a value has been set for the field or property. Because the special field must not be serialized, the tool applies the XmlIgnoreAttribute to it.

For more information about using attributes, see the conceptual topic at MSDN: extendingmetadatausingattributes.

Note In your code, you can use the word XmlIgnore instead of the longer XmlIgnoreAttribute.

The following example shows a class named Group, which contains a field named Comment. The example assigns the XmlIgnoreAttribute to the field, thereby instructing the XmlSerializer to ignore the field when serializing or deserializing an instance of the class.

public class Group
{
   // The XmlSerializer ignores this field.
   [XmlIgnore]
   public string Comment;

   // The XmlSerializer serializes this field.
   public string GroupName;
}
   

    

System.Xml.Serialization Namespace | XmlAttributeOverrides | XmlAttributes | XmlAttributes.XmlIgnore | XmlSerializer | MSDN: introducingxmlserialization | MSDN: overridingserializationofclasseswithxmlattributeoverridesclass | XmlAttributes | MSDN: controllingserializationbyxmlserializerwithattributes | MSDN: anexampleofxmlserializationwithxmlserializer

System.Xml.Serialization.XmlIgnoreAttribute Member List:

Public Constructors

ctor #1

Default constructor. This constructor is called by derived class constructors to initialize state in this type. Initializes a new instance of the XmlIgnoreAttribute class.

Public Properties

TypeId (inherited from System.Attribute)

Read-only See base class member description: System.Attribute.TypeId When implemented in a derived class, gets a unique identifier for this Attribute.

Public Methods

Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetHashCode (inherited from System.Attribute)	See base class member description: System.Attribute.GetHashCode Returns the hash code for this instance.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IsDefaultAttribute (inherited from System.Attribute)	See base class member description: System.Attribute.IsDefaultAttribute When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.
Match (inherited from System.Attribute)	See base class member description: System.Attribute.Match When overridden in a derived class, returns a value indicating whether this instance equals a specified object.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

• System.Object
• System.Attribute
• System.Xml.Serialization.XmlIgnoreAttribute

System.Xml.Serialization.XmlIgnoreAttribute Member Details

Summary

Initializes a new instance of the XmlIgnoreAttribute class.

Default constructor. This constructor is called by derived class constructors to initialize state in this type.

C# Syntax:

public XmlIgnoreAttribute();

The following example shows a class named Group, which contains a field named Comment. The example assigns the XmlIgnoreAttribute to the field, thereby instructing the XmlSerializer to ignore the field when serializing or deserializing an instance of the class.

public class Group
{
   // The XmlSerializer ignores this field.
   [XmlIgnore]
   public string Comment;

   // The XmlSerializer serializes this field.
   public string GroupName;
}
   

    

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Inherited
See base class member description: System.Attribute.TypeId

Summary

When implemented in a derived class, gets a unique identifier for this Attribute.

C# Syntax:

public virtual object TypeId {get;}

As implemented, this identifier is merely the Type of the attribute. However, it is intended that the unique identifier be used to identify two attributes of the same type.

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Inherited
See base class member description: System.Object.Equals

C# Syntax:

public virtual bool Equals(    object obj );

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~XmlIgnoreAttribute();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Attribute.GetHashCode

Summary

Returns the hash code for this instance.

C# Syntax:

public override int GetHashCode();

Return Value:

A 32-bit signed integer hash code.

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Attribute.IsDefaultAttribute

Summary

When overridden in a derived class, returns an indication whether the value of this instance is the default value for the derived class.

C# Syntax:

public virtual bool IsDefaultAttribute();

Return Value:

true if this instance is the default attribute for the class; otherwise, false.

The default implementation of this class returns false, and must be implemented in the derived class to be useful to that class.

The implementation of this method in a derived class compares the value of this instance to a standard, default value obtained by some means, then returns a Boolean value that indicates whether the value of this instance is equal to the standard. The standard value is typically coded as a constant in the implementation, or stored programmatically in a field used by the implementation.

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Inherited
See base class member description: System.Attribute.Match

Summary

When overridden in a derived class, returns a value indicating whether this instance equals a specified object.

C# Syntax:

public virtual bool Match(    object obj );

obj

An Object to compare with this instance of Attribute.

Return Value:

true if this instance equals obj; otherwise, false.

This method determines if one Attribute equals another. Its default implementation is the same as Attribute.Equals, which performs a value and reference comparison. Override this method to implement support for attribute values, such as flags or bitfields, that consist of components that are meaningful in themselves. For example, consider an attribute whose value is a binary field divided into a bitfield of flags. Two instances of this attribute have one flag in set in common while all the other flags differ. The Equal method cannot determine that the two instances have the same flag set, but the Match method can.

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.ToString

C# Syntax:

public virtual string ToString();

For more information on members inherited from System.Object click on the link above.

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